Identification of Mercury Emissions in Soot with the Quadrant Method on Combustion of Gold in Aceh Jaya District

Abstract

BACKGROUND: Gold mining, especially by the community, causes many problems. One of the problems is the increase in mercury pollution. The amalgamation technique involving mercury in the gold processing process is still widely used by miners and has the potential to threaten the health of workers and the surrounding community. AIM: This study aimed to identify mercury levels in soot at the location of a traditional gold processing plant in Paya Seumantok Village, Krueng Sabee District, Aceh Jaya District. METHODS: This research was conducted at the Environmental Quality Analysis laboratory, Chemical Engineering Department, Syiah Kuala University, Banda Aceh, in May–August 2021. The sample in this study was soot caught on cloth attached to the gold kiln location by amalgamation using the quadrant method. The soot sample was obtained from the people’s gold processing unit in Gampong Paya Seumantok, Krueng Seabee District; then, the fabric sample containing soot was destroyed using HNO3 in the microwave. Measurement of mercury levels, using AAS Perkin-Elmer Analyst 600, equipped with Graphite Furnace (AAS) Technique. RESULTS: The results of the identification show that the mercury level in the first stage of measurement found the highest mercury concentration at a distance of 10 cm with a concentration of 41.90 (±21.64) g-Hg/g, a distance of 5 cm was obtained at 28.71 (±11. 0.98) g-Hg/g, and at a distance of 15 cm obtained 28.20 (±2.85) g-Hg/g. Furthermore, in the measurement of samples in stages 2 and 3, the mercury concentration in soot is influenced by distance, where the closer the distance, the higher the mercury concentration. Stage 2 measurement at a distance of 5 cm, the mercury concentration obtained is 26.84 (±21.05) g-Hg/g, a distance of 10 and 15 cm each has a concentration of 9.25 (±1.26) g-Hg/g and 9.91 (±3.59) g-Hg/g, and in the third stage of the test, the highest concentration located at a distance of 5 cm with a concentration of 20.27 (±3.57) g-Hg/g. CONCLUSION: The average value of mercury concentration in soot obtained far exceeds the threshold set by the World Health Organization, which is 1 g-Hg/gram. Mercury levels that have exceeded the threshold need to be filtered in an enclosed space before the smoke from burning gold spreads into the free air.